Safety-stop device



- K. MILLER SAFETY-STOP DEVICE Filed Sept. 18 1 .967

April 28, v

- ATTOR NEY United States Patent US. 'Cl. 307119 7 Claims ABSTRACT OF THE DISCLOSURE This invention is concerned essentially with a safety stop for power-operated devices wherein an annular resiliently depressible assembly includes normally spaced annular contacts movable into engagement upon depression of the assembly and electrically connected to a power source to be operated.

SUMMARY It is an important object of the present invention to provide a safety stop of the type described which is entirely reliable in operation, being operable even after severe mutilation or damage, including severance of the internal conductors.

It is still another object of the present invention to provide a safety stop having the advantageous characteristics mentioned in the preceding paragraph, which is relatively simple in construction, durable throughout a long useful life even under adverse conditions of use, and which can be economically manufactured and installed for sale at a reasonable price.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings, which form a material part of this disclosure.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, which will be exemplified in the construction hereinafter described, and of which the scope will be indicated by the appended claims.

BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a top perspective view illustrating the safety stop of the present invention, partly broken away to show internal construction.

FIGURE 2 is a top view, partly in section, illustrating construction of the instant device, and showing electrical circuitry associated therewith.

FIGURE 3 is a partial sectional elevational view taken generally along the line 33 of FIGURE 2, but illustrating the device in a depressed condition of operation.

FIGURE 4 is a partial horizontal sectional view taken generally along the line 44 of FIGURE 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now more particularly to the drawing, and specifically to FIGURE 1 thereof, a safety stop of the present invention is there generally designated 10, including an upstanding support or post 11, and an annular assembly 12 circumposed about the post.

The annular assembly 12 includes an inner annulus 13 of a constant, generally rectangular cross section throughout its length, circumposed about the support 11, adjacent thereto. The inner annulus 13 is preferably fabricated of resiliently yieldable and nonconductive material, such as plastic foam. Circumposed about the inner annulus 13,

covering the outer periphery thereof and secured in facing engagement therewith, is an annular inner conductor 14, say of metal foil, or other suitable conductive flexible sheet material.

An intermediate array of resiliently yieldable material is designated 15, being circumposed about the inner conductor 14. The annular array 15 may be formed of a sheet of resiliently yieldable, nonconductive material, such as plastic foam, and is advantageously formed with a plurality of relatively large thru openings 16. Thus, the annular array 15 is of an openwork construction, the openings 16 extending radially therethrough.

An outer conductor 17 is circumposed about the openwork array 15, covering the latter, and in radially spaced facing relation with respect to the inner conductor 14. In particular, radially spaced portions of the inner and outer conductors 14 and 17, as at 1'8 and 19, are disposed in spaced confronting relation opening into a single hole or aperture 16 of the intermediate foam layer 15. The outer conductor 17 is also advantageously fabricated of suitably flexible conductive sheet material, such as metal foil.

Circumposed about the outer conductor 17 is an outer annulus 20 in facing engagement with and covering the outer side of the outer conductor, preferably adhesively or otherwise secured thereto. The outer annulus 20 may be fabricated of plastic foam, or other suitable nonconductive, resiliently yieldable material and is generally of a constant rectangular cross section throughout its length, having a width substantially equal to that of the inner annulus 13.

Completely enclosing the assembly of inner and outer annuli 13 and 20, inner and outer conductors 14 and 17, and intermediate array 15, is a hermetically sealed flexible sheet casing 22. The casing may advantageously be fabricated of impermeable flexible plastic or other sheet material, conformably enclosing the contents thereof, and may include an inner wall 23 extending about and covering the inner side of the inner annulus 13, a pair of generally circular end walls 24 extending from opposite ends of the inner wall 23 across the ends of the annuli 13 and 20, conductors 14 and 17, and intermediate array 15. An outer wall 25 may extend about the external side of outer annulus 20, having its opposite edges secured by heatsealing or other suitable means to the adjacent margins of end walls 24. The casing 22 thus hermetically seals the annular assembly 12, and may be provided with suitable securement means (not shown) for securing the assembly to the support 11, if desired.

An actuating circuit is generally designated 28, and shown in FIGURE 2 as including a relay coil 29 associated with a normally closed relay switch 30. The switch 30 is connected in circuit with a power source operating a power device, say, a door, radome, or the like, as by conductors 31 and 32. The relay coil 29 may be connected, as by a conductor 33 to one side of a power source or battery 34, and connected by a conductor 35 to an alarm 36, say audible and/or visual. The other side of the battery 34 is connected by a conductor or wire 37 to one of the annular conductors, say the outer conductor 17, while the alarm 36 is connected by a conductor 38 to the other of the annular conductors, say the inner conductor 14.

The normal operating condition of the electrical-circuit means is shown in FIGURE 2, with the switch 30 closed and the coil 29 deenergized. However, upon engagement of inner and outer electrically continuous annular conductors 14 and 17, a circuit is closed through the battery 34, the annular conductors, alarm 36 and relay 29. The alarm is thereby energized, and the switch 30 is opened to deenergize the motor or other power-operated device.

It will now be apparent, that even should the annular assembly 12 become severely damaged, as by cutting through of one or both of the inner and outer annular conductors 14 and 17 to destroy electrical continuity thereof, contact between the annular conductors will effect the desired circuit closure. Such contact is illustrated in FIGURES 3 and 4, wherein a movable member or arm 40 is illustrated as depressing the outer annulus 20 radially inward, the latter moving the outer conductor 17 radially inward through one of the openings 16, to place opposite conductor portions 19 and 18 in contact with each other.

From the foregoing, it is seen that the present invention provides a safety stop which fully accomplishes its intended objects and is well adapted to meet practical conditions of manufacture, installation and use.

Although the present invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be made within the spirit of the invention and scope of the appended claims.

What is claimed is:

=1. A safety stop for power-operated devices, said stop comprising a fixed support; an annular assembly circumposed about said support and comprising an inner annulus of nonconductive resiliently yieldable material circumposed about said support, an inner annular electrically continuous conductor circumsposed about said inner annulus, an annular intermediate array of nonconductive resiliently yieldable material circumposed about said inner conductor and having a plurality of thru radial openings, an outer electrically continuous annular conductor circumposed about said intermediate array having portions overlying the openings of said intermediate array with the overlying portions in spaced facing relation with radially inwardly portions of said inner conductor, and an outer annulus of nonconductive resiliently yieldable material circumposed about said outer conductor; a hermetically sealed flexible sheet casing enclosing said assembly; electrical actuating means externally of said assembly for connection to a power source to deenergize a power-operated device; and electrical-circuit means connected through said actuating means and to said inner and outer conductors; whereby radial depression of said assembly efi'ects contact of facing conductor portions to close said circuit means and operate said actuating means.

2. A safety stop according to claim 1, said inner annulus, intermediate array and outer annulus being of foam.

3. A safety stop according to claim 2, said intermediate array comprising a single foam sheet having apertures therethrough defining said openings.

4. A safety stop according to claim 1, said inner and outer conductors being fabricated of metal foil and respectively secured in facing relation with said inner and outer annuli.

5. A safety stop according to claim 1, said actuating means comprising relay means.

6. A safety stop according to claim 1, in combination with an alarm connected to said actuating means for actuation thereby.

7. A safety stop according to claim 1, said annular assembly being of a constant generally rectangular crosssectional configuration throughout its length, and said inner and outer annuli being of generally rectangular cross-sectional configuration throughout their lengths.

References Cited UNITED STATES PATENTS 2,128,058 8/1938 Shaw 200'86 2,790,873 4/1957 Fleming 200'86 3,315,050 4/1967 Miller 20086 X 3,321,592 5/1967 Miller 20086 X 3,323,197' 6/1967 Millard ZOO-86 X ROBERT K. SCHAEFER, Primary Examiner T. B. J OIKE, Assistant Examiner US. Cl. X.R. 20086 

